Marianas Trench

The Mariana Trench is the deepest known part of the world's oceans, located in the western Pacific Ocean. Its deepest point, Challenger Deep, reaches approximately 10,984 meters (36,037 feet) below sea level. The trench is named after the nearby Mariana Islands and was formed by the subduction of the Pacific Plate beneath the Mariana Plate.

Mariana Trench Wikipedia page

Key Facts About the Mariana Trench:

Location: Western Pacific, near Guam and the Mariana Islands.
Depth: ~10,984 meters (Challenger Deep).
Pressure: Over 1,000 atmospheres (8 tons per square inch).
Temperature: Near freezing (1–4°C) due to lack of sunlight.
Lifeforms: Unique extremophiles, including amphipods, snailfish, and microbial life adapted to extreme pressure.

Submersibles That Have Visited the Mariana Trench:

Only a few crewed and uncrewed vehicles have reached the bottom of the trench.

1. Trieste (1960) – First Crewed Descent

Pilots: Jacques Piccard & Don Walsh (US Navy).
Depth: ~10,916 meters (35,814 ft).
Key Fact: The bathyscaphe’s windows cracked on descent, but they confirmed life at extreme depths.

2.

3. Limiting Factor (2019) – Multiple Dives by DSV Limiting Factor

Organization: Caladan Oceanic (Victor Vescovo).
Depth: Multiple dives to ~10,925 meters (35,843 ft).
Key Fact: First repeated crewed dives, mapping new species and plastic pollution.

1. Trieste (1960) – First Crewed Descent Pilots: Jacques Piccard & Don Walsh (US Navy).

2. Deepsea Challenger (2012) – James Cameron’s Solo Dive

Pilot: James Cameron (filmmaker & explorer).
Depth: ~10,908 meters (35,787 ft).
Key Fact: Cameron spent ~3 hours collecting samples and filming for documentaries.

4. Uncrewed Vehicles:

Kaikō (1995, Japan) – First robotic probe to reach Challenger Deep (retired in 2003).
Nereus (2009, USA) – Hybrid remotely operated vehicle (ROV) that imploded in 2014.
Hadal Exploration System (2020, China – "Fendouzhe") – Crewed and uncrewed dives to ~10,909 meters.